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Nagashima Ohno & Tsunematsu

Work +81 3 6889 7000
Fax +81 3 6889 8000

Ryoichi Mimura

Work +81 3 6889 7175
Nagashima Ohno & Tsunematsu


General Corporate; IP, IT and Entertainment; IP Transactions; IP Litigation; Dispute Resolution


Judge of Tokyo District Court (1989-1993; IP Division, 1989-1991); Judicial Research Official of Supreme Court (IP & Civil Matters; 1993-1998); Presiding Judge of Tokyo District Court (IP Division; 1998-2005); Judge of Intellectual Property High Court (2005-2008); Judge of Tokyo High Court (2008-2009); Admitted to Bar (2009); Partner at Nagashima Ohno & Tsunematsu (2009-Present); Visiting Professor, Waseda Law School (2010-Present)


Japanese, German and English.


Copyright Law Association of Japan, Japan Association of Industrial Property Law and German-Japanese Association of Jurists


The University of Tokyo (LL.B., 1977); The University of Cologne (Germany) (1981-1983)

Japan: Dispute resolution

Independent local firms

Within: Independent local firms

Norimitsu Arai heads up the ‘leading’ department at Nagashima Ohno & Tsunematsu, which ‘provides a truly great service, especially in terms of responsiveness and business acumen’. With a key strength in international arbitration, the group also handles litigation in the labour and employment space (a key area of focus of Arai), IP (through Ryoichi Mimura), and product liability and environmental tort matters (thanks to the experience of the ‘responsive and thoughtfulHisaya Kimura). Recent highlights include representing Tepco in a shareholders derivative dispute relating to the Fukushima earthquake and power plant disaster, and acting for multiple banks in a suit for damages against Olympus relating to the losses incurred by its filing of false financial reports. Further clients include Merrill Lynch Japan Securities, Samsung and IBM.

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Japan: Intellectual property

Independent local firms

Within: Leading individuals: bengoshi

Ryoichi Mimura - Nagashima Ohno & Tsunematsu

Within: Independent local firms

Nagashima Ohno & Tsunematsu handles matters related to patent work, unfair competition, copyright and trade mark and design protection. The practice successfully acted for Japanese chemical engineering and manufacturing company Nichia against Tachibana Eletech in an unfair competition matter. Other clients include Alcon Research and Yamaha. Former judge at the Intellectual Property High Court Ryoichi Mimura is recommended.

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Japan: TMT

Independent local firms

Within: Independent local firms

Nagashima Ohno & Tsunematsu advises major Japanese telecoms providers and TV networks, as well as domestic and international internet, social media and gaming companies, in transactions, disputes and regulatory matters. The practice assisted Innovation Network Corporation of Japan with an exit transaction to sell all its shares in Digital Publishing Initiatives Japan. Itochu, Pioneer and Airbnb are other clients. Practice head Ryoichi Mimura, who has expertise in technology-related disputes and IP, is recommended, as is Soichiro Fujiwara.

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Legal Developments in Japan

Legal Developments and updates from the leading lawyers in each jurisdiction. To contribute, send an email request to
  • Taking control of a Japanese publicly listed company:

    Introductory notes for successfully completing an M&A
  • Yuasa and Hara Business Law News

    Contents of the Issue Law on liability for breach of contract Review on the amendment to the cabinet office order on Corporate Disclosure

    The Minister for Justice, Alan Shatter (“the Minister”), has published the Criminal Justice Bill 2011 (“the Bill”). The main purpose of the Bill is stated to be “…to amend the criminal law to improve certain procedural matters and strengthen Garda investigative powers. The intention is that such improvements will assist in reducing the delays associated with the investigation and prosecution of complex crime, in particular white collar crime.”
  • Japan: New legislative framework for Sukuk

    The new framework passed in May 2011 will provide a solid legal platform for issuing Sukuk Ijarah under Japanese law. NAOKI ISHIKAWA highlights key legal structures and tax treatment in respect of the anticipated Sukuk issuances in Japan.
  • Yakult Bottle Acquired Distinctiveness

    Do you know about Yakult's delicious lactic acid drink which is contained in a small bottle? Yakult's lactic acid drink (hereafter referred to as "Yakult drink") is the most famous lactic acid drink in Japan and today is also being sold in many countries around the world. When you are enjoying Yakult drink, please keep in mind the case mentioned below.
  • Tax: Japan: International Joint Ventures

    Tax on international joint ventures. Country Q&A (Japan).
  • Japan: Recent Developments in Practice and Law

    The successful closing of two Islamic fi nance transactions which was announced in July 2010 by Nomura Holdings have paved a concrete path for Japanese corporations to consider overseas Islamic fi nance markets for their fund raising activities. The fi rst transaction was in Asia for the issuance of Sukuk Ijarah and the second was in the Middle East for the establishment of a Commodity Murabahah facility (Nomura Deals).
  • Renewable energy takes off in Japan

    Like many other countries, Japan has decided to reform its renewable energy (RE) policy, to dramatically increase the use of renewable energy. The core policy mechanism is a feed-in tariff (FIT). This chapter summarises the contemplated Japanese FIT and its practical impact on existing and future investment in this sector, providing an overview of:
  • Licensing - 2010

    Q & A on Licensing in Japan 
  • Law on the Civil Jurisdiction of Japanese Courts over Foreign Countries, etc.

    The Law has been enacted to clarify the scope of application of the civil jurisdiction of Japanese courts over foreign countries, etc., and set exceptions to civil preocedings involving foreign countries, etc., based on the United Nations Convention on the Jurisdictional Immunities of States and their property (UN Convention on Immunities) (see Article 1).